Gpz motor tranny and standard?

I was wondering, my 550 Gpz had a 6 speed, my 750 has a 5.

Are they interchangable? I think its weird everytime I shift to 6th and its not there.

I dont mean a 550 tranny, i mean Gpz 750's also have 6 gears right?

Post edited by: ran429, at: 2006/03/01 21:04

Well, I can't speak for the later GPz's, but the 1982 (Z750R1) and the 1983 (ZX750A1) models are 5 speed.

Is there anything stamped on the case where the gear change lever enters ? Mine has a little box which shows
5
4
3
2
0
1

........................................................................................
Woodstock ON Canada
1980 kz750E1, 4->1, K&N pods

I believe all the gpz are 6 speed with same gearing. There was a Thread not too long ago on someone doing a six speed swap into a 650, but something with the kickstart prevented it. The six speed dropped into the750.

The 550's were 6 speed, the 750's were 5 speed.

I'm in the middle of installing a GPz550 six speed transmission in an 83 GPz750 motor right now, should be done in a day or two.

Post edited by: steell, at: 2006/03/02 16:37

I am sure there is an old thread or two in the archive on this topic. Steell: give us the details on your six speed swap. Inquiring minds want to know if this makes sense to consider for our 750s.

steell wrote:

The 550's were 6 speed, the 75's were 5 speed.

I'm in the middle of installing a GPz550 six speed transmission in an 83 GPz750 motor right now, should be done in a day or two.

Well, let me know how it ends up on final test please? I am really interested in the outcome.

It's not my motor, I'm doing it for another guy (a member here), IIRC first gear is geared just a little lower and high gear (6th) is geared just a little higher in the six speed transmissions vs the five speeds.
The 83-85 GPz750 is just a little peaky, the power comes in at higher rpm, so the idea is to get another gear in there to keep the motor in it's powerband.
This one has a shaved head and an 810 kit, so it ought to run pretty good, unfortunately it's not mine

Post edited by: steell, at: 2006/03/02 16:49

is it just a drop in modd or is there alot of modifications going on? what about the shifting forks/drum? what parts are needed for this?

You need both transmission shafts with all the gears, the shifting drum and all three shift forks from the 550 six speed trans. I can assure you that even though the 750 and 550 shift forks look almost identical, they "will not" interchange. This motor was dropped off here dismantled and in a box (and anyone that builds motors knows what that's like) and the trans parts were mixed together. Good thing I enjoy a good challenge :laugh:

No mods needed in a GPz750, and I believe the KZ750 bottom end is identical, so it should be a drop in operation for the KZ750 models as well. I don't know if it would work in a kickstart 650 though, I have not tried it. Oh yeah, when installing it in a 83-85 GPz750 motor, a stock GPz750 offset sprocket is still required.

Post edited by: steell, at: 2006/03/03 08:36

Thank you for clearing that up for me steel.